package com.xinjian.netty;

import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.handler.timeout.IdleState;
import io.netty.handler.timeout.IdleStateEvent;

/**
 * 用于检测channel的心跳handler 继承ChannelInboundHandlerAdapter，从而不需要实现channelRead0方法
 *
 * @author yyb
 * @create 2018-12-27-19:58
 */
public class HeartBeatHandler extends ChannelInboundHandlerAdapter {

    @Override
    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {

        // 判断evt是否是IdleStateEvent（用于触发用户事件，包含 读空闲/写空闲/读写空闲 ）
        if (evt instanceof IdleStateEvent) {
            IdleStateEvent event = (IdleStateEvent) evt;//强制类型转换
            if (event.state() == IdleState.READER_IDLE) {
                System.out.println("进入读空闲。。。");
            } else if (event.state() == IdleState.WRITER_IDLE) {
                System.out.println("进入写空闲。。。");
            } else if (event.state() == IdleState.ALL_IDLE) {

                System.out.println("channel关闭前，users的数量为：" + ChatHandler.users.size());
                Channel channel = ctx.channel();
                //关闭无用的channel, 以防资源浪费
                channel.close();
                System.out.println("channel关闭前，users的数量为：" + ChatHandler.users.size());

            }


        }

    }


}
